Currently, intravenous infusion is the most common and widespread clinical method in clinical treatment of foreign and domestic medical institutions, according to investigation, 90% of patients are subject to treatment of intravenous injection. Almost 100% of inpatients for surgery need to take the intravenous injection, and according to statistics of related departments, for 1.3 billion people in China, each person is subject to up to 8 dropping bottles annually on average, and infusion quantity reaches up high to 10.4 billion bottles. Nowadays, with improvement in science and technology as well as rapid development in medical field, a conventional infusion method still uses a fixed hanger invented by “Murphy” more than one hundred years ago, i.e. hang over a dropping bottle (pack) at a position higher than a puncture site of a patient to a certain height.
This conventional infusion method needs assistance from a fixed hanger mainly due to the limitations of infusion dynamics, which has many defects during practical use: 1) a patient is in a relatively fixed posture, and activities thereof are restricted apparently, it may be seen in medical institutions that a patient lifts an infusion bottle by oneself or lifts an infusion bottle escorted by the family to walk up and down stairs for various examinations, even goes to the bathroom; 2) it is difficult to transport the wounded, outside the hospital, there is no sufficient space to rotate a dropping bottle during battlefield and field rescue as well as patient transportation (using ambulance), the dropping bottle swings too much during driving, which is neither safe nor efficient for infusion, to transport the wounded at the battlefront, position thereof may be given away easily when the infusion rack and liquid sway, which is of poor concealment; and 3) infusion speed cannot be controlled accurately, during a process of saving high risk patients who are subject to severe loss of blood and dehydration, accurately injecting certain amount of liquid within a specified time cannot be implemented.
In addition to the conventional method above, an automatic pneumatic-type infusion device, an automatic pump-type infusion device, and a microcontroller-based portable medical automatic infusion device occur in recent years.
For the automatic pneumatic-type infusion device, a gas delivering pipeline is connected to a gas delivering pump at one end, and air is injected into the liquid bottle by the pump via an air filter to increase pressure within the liquid bottle, so that an objective of automatic infusion is achieved. Its defects lie in that, an infusion rack is also needed to hang the liquid bottle and an extra power source and gas delivering pump are needed, which generally does not have obvious advantages compared to the conventional method;
For the automatic pump-type infusion device and the microcontroller-based portable medical automatic infusion device, their main structure is a unique piping system formed of a dropping pack, a pump chamber, a pipeline and an injection needle. An integrated circuit controls a pushing lever to press the pump chamber, and automatic infusion is achieved by pipeline external control, various liquid medicines may be injected into veins in a specified amount at regular time. Hanging is avoided during infusion, the patient may move freely, however, the defects lie in that, the infusion pump has a large volume and needs to be driven by a power source, which requires high techniques and is difficult to be used widely in medical institutions at different levels.
An automatic inflatable pack-type infusion device includes an air bag, two independent chambers, a liquid filling pipe and an inflatable pipe, where the two chambers are separated by a flexible spacer layer, the inflatable pipe is in communication with one chamber, and the liquid filling pipe is in communication with the other chamber, and gas is pressed into space between an inner pack and an outer pack of an infusion pack with hands by utilizing one gasbag, so that pressure is generated from liquid within the inner pack, and the liquid is injected into patient body in a controllable the flow rate by pressure. The device is easy for use and convenient for carry (which may be hung around waist), and defects such as blood return will not occur. Principles of the automatic inflatable pack-style infusion device are fundamentally the same with principles of pressurized blood transfusion commonly used in clinical, of which a defect lies in a need for a continuous manual inflation, otherwise the liquid cannot overcome resistance from the blood to enter into blood vessels, thus burden for conventional infusion management is increased and the device is difficult to be promoted and used in the clinic treatment.